The paper describes what would happen to humans and other mammals if global temperatures were to rise a certain amount over the course of this century

A Purdue climatologist has published a paper that questions, "How much warming can humans physically handle?"

Matthew Huber, a Purdue University climatologist, wrote a scientific paper that describes what would happen to humans and other mammals if expected rises in global temperature were to occur by the year 2100. Average estimates from certain models land in the 3 to 4 degrees Celsius range, while others predict 10 or even 20 degree hikes.

Using a measurement technique called "wet-bulb temperature," Huber and Sherwood were able to model what would happen to humans if the 3, 4, 10 or 20 degree increases were to occur by 2100. The wet-bulb temperature method consists of a thermometer bulb wrapped in wet cloth and ventilated, which represents the most perfect scenario for a human to withstand increasing global temperatures: a naked, healthy adult standing in the shade while drinking gallons and gallons of water. Any other scenario that strays from this perfect example would place heat-related stress on a person or mammal to some degree depending on the increase in global temperature.

"We intentionally were trying to explore the upper limit of what humans can possibly stand," said Huber. "Essentially we were assuming a perfectly acclimated person, in perfect health, not performing physical labor, and out of the sun, and were then asking, 'What would it take to kill them quickly?' A real person would be profoundly uncomfortable, miserable and/or sick long before we reach the limit discussed in our paper. Infants, pregnant women, and the elderly would be especially vulnerable long before we hit the limit discussed.

"Thus, the global mean temperature increase of about >10°C that causes widespread heat death in our paper probably is a significant overestimate of the threshold at which substantial harm [would come] to societies and individuals would suffer harm and/or reduced productivity. Put in more prosaic terms, large parts of the world would be violating OSHA and international health standards for work long before we approach this >10°C threshold. But we wanted to be sure we had a limit set by physical and thermodynamic laws and not by human ones (since those are mutable)."

According to Huber, it's most important for the world to set a goal of what temperature increase to avoid. He believes avoiding a 2 degree Celsius increase by 2100 would be impossible by this point, but maybe a 6 degree (and definitely 10 degree) increase is preventable if the proper actions are taken.

If a 10 or 12 degree global temperature increase was achieved by 2100, Huber said people would likely be dying in the streets or running to air conditioned-only locations. However, increased air conditioning can lead to power grid issues, and the grid is strained enough as it is.

What would the world be like if we hit a 12 degree Celsius increase?

"My nightmare," said Huber. "I'm in Oklahoma on a hot summer day. Under a heat lamp. Running. Wrapped in plastic."

There is much debate over whether climate models are correct or not, so Huber's method of basing his results of off many of them (which have varied results of 3 to 20 degree Celsius predicted hikes by 2100) have caused scientists to be skeptical.

"The models aren't perfect," said Huber. "The thing to ask is, are they biased to produce a world that is too warm or too cold in the future? For 30 years, climate modelers have compared simulations of past climate change (glacial intervals, greenhouse climates such as the Eocene) against data and found that models get the general climate right but that they are systematically biased to be somewhat too insensitive to forcing. In other words, what modeling of past climates tells us is that these models are—if anything—biased to underpredict future climate change."

Another question addressed is whether humans can adapt to the increase in global temperature. Huber seems to think some can through burrowing, staying near bodies of water, reducing activities and becoming more active at night.

"The most direct way for humans to respond physiologically, which would take thousands of years if at all (we are most likely to change our behaviors) is to get small and skinny, to decrease our volume and maximize our surface area so we can lose heat more effectively," said Huber.

Earlier this week, ExxonMobil CEO Rex Tillerson said that manmade global warming has been overexaggerated, and that humans could easily adapt to rising global temperatures. He also blamed a lazy press, illiterate public and fear-mongering advocacy groups for the bad light placed on the oil industry.

"We have spent our entire existence adapting," said Tillerson. "We'll adapt. It's an engineering problem and there will be an engineering solution."

Huber and Sherwood's paper was published in the Proceedings of the National Academy of Sciences.

quote: If your support for the CO2 causes warming is based on science and rationality and not faith then I presume that you would accept that the hypothesis that CO2 drives warming, like all scientific hypothesis, offers the opportunity to be disproved by real world observed data.

correct! and *real world" observed data shows that to be the case. stop with your fud and actually try to understand what the science says.

quote: correct! and *real world" observed data shows that to be the case. stop with your fud and actually try to understand what the science says.

Can I ask what real world evidence?

I started out being agnostic on the issue of whether CO2 was causing warming and if it was whether it was dangerous or not. I just didn't know much about it, but it seemed to be an important issue so I spent a lot of time looking at the evidence that was used to support the theory that CO2 was driving dangerous climate change. I was really surprised at how poor that evidence was and how little the supporters of the theory wanted to discuss the evidence in any detail.

I am prepared to change my mind on this issue if the evidence convinces me to do so. So please can anyone actually point me towards the evidence that supports the theory that CO2 is driving dangerous climate change and that the recent small changes in global temperature are not just natural climate variation?